1. Field of the Invention
The present invention relates to reservations in a compute environment and more specifically to a system and method of providing advanced reservations to resources within a compute environment such as a cluster.
2. Introduction
There are challenges in the complex process of managing the consumption of resources within a compute environment such as a grid, compute farm or cluster of computers. Grid computing may be defined as coordinated resource sharing and problem solving in dynamic, multi-institutional collaborations. Many computing projects require much more computational power and resources than a single computer may provide. Networked computers with peripheral resources such as printers, scanners, I/O devices, storage disks, scientific devices and instruments, etc. may need to be coordinated and utilized to complete a task. The term compute resource generally refers to computer processors, network bandwidth, and any of these peripheral resources as well. A compute farm may comprise a plurality of computers coordinated for such purposes of handling Internet traffic. The web search website Google® had a compute farm used to process its network traffic and Internet searches.
Grid/cluster resource management generally describes the process of identifying requirements, matching resources to applications, allocating those resources, and scheduling and monitoring grid resources over time in order to run grid applications or jobs submitted to the compute environment as efficiently as possible. Each project or job will utilize a different set of resources and thus is typically unique. For example, a job may utilize computer processors and disk space, while another job may require a large amount of network bandwidth and a particular operating system. In addition to the challenge of allocating resources for a particular job or a request for resources, administrators also have difficulty obtaining a clear understanding of the resources available, the current status of the compute environment and available resources, and real-time competing needs of various users. One aspect of this process is the ability to reserve resources for a job. A cluster manager will seek to reserve a set of resources to enable the cluster to process a job at a promised quality of service.
General background information on clusters and grids may be found in several publications. See, e.g., Grid Resource Management, State of the Art and Future Trends, Jarek Nabrzyski, Jennifer M. Schopf, and Jan Weglarz, Kluwer Academic Publishers, 2004; and Beowulf Cluster Computing with Linux, edited by William Gropp, Ewing Lusk, and Thomas Sterling, Massachusetts Institute of Technology, 2003.
It is generally understood herein that the terms grid and cluster are interchangeable, although they have different connotations. For example, when a grid is referred to as receiving a request for resources and the request is processed in a particular way, the same method may also apply to other compute environments such as a cluster or a compute farm. A cluster is generally defined as a collection of compute nodes organized for accomplishing a task or a set of tasks. In general, a grid will comprise a plurality of clusters as will be shown in FIG. 1A. Several general challenges exist when attempting to maximize resources in a grid. First, there are typically multiple layers of grid and cluster schedulers. A grid 100 generally comprises a group of clusters or a group of networked computers. The definition of a grid is very flexible and may mean a number of different configurations of computers. The introduction here is meant to be general given the variety of configurations that are possible. A grid scheduler 102 communicates with a plurality of cluster schedulers 104A, 104B and 104C. Each of these cluster schedulers communicates with a respective resource manager 106A, 106B or 106C. Each resource manager communicates with a respective series of compute resources shown as nodes 108A, 108B, 108C in cluster 110, nodes 108D, 108E, 108F in cluster 112 and nodes 108G, 108H, 108I in cluster 114.
Local schedulers (which may refer to either the cluster schedulers 104 or the resource managers 106) are closer to the specific resources 108 and may not allow grid schedulers 102 direct access to the resources. The grid level scheduler 102 typically does not own or control the actual resources. Therefore, jobs are submitted from the high level grid-scheduler 102 to a local set of resources with no more permissions that then user would have. This reduces efficiencies and can render the reservation process more difficult.
The heterogeneous nature of the shared compute resources also causes a reduction in efficiency. Without dedicated access to a resource, the grid level scheduler 102 is challenged with the high degree of variance and unpredictability in the capacity of the resources available for use. Most resources are shared among users and projects and each project varies from the other. The performance goals for projects differ. Grid resources are used to improve performance of an application but the resource owners and users have different performance goals: from optimizing the performance for a single application to getting the best system throughput or minimizing response time. Local policies may also play a role in performance.
Within a given cluster, there is only a concept of resource management in space. An administrator can partition a cluster and identify a set of resources to be dedicated to a particular purpose and another set of resources can be dedicated to another purpose. In this regard, the resources are reserved in advance to process the job. There is currently no ability to identify a set of resources over a time frame for a purpose. By being constrained in space, the nodes 108A, 108B, 108C, if they need maintenance or for administrators to perform work or provisioning on the nodes, have to be taken out of the system, fragmented permanently or partitioned permanently for special purposes or policies. If the administrator wants to dedicate them to particular users, organizations or groups, the prior art method of resource management in space causes too much management overhead requiring a constant adjustment the configuration of the cluster environment and also losses in efficiency with the fragmentation associated with meeting particular policies.
To manage the jobs submissions or requests for resources within a cluster, a cluster scheduler will employ reservations to insure that jobs will have the resources necessary for processing. FIG. 1B illustrates a cluster/node diagram for a cluster 124 with nodes 120. Time is along the X axis. An access control list 114 (ACL) to the cluster is static, meaning that the ACL is based on the credentials of the person, group, account, class or quality of service making the request or job submission to the cluster. The ACL 114 determines what jobs get assigned to the cluster 110 via a reservation 112 shown as spanning into two nodes of the cluster. Either the job can be allocated to the cluster or it can't and the decision is determined based on who submits the job at submission time. The deficiency with this approach is that there are situations in which organizations would like to make resources available but only in such a way as to balance or meet certain performance goals. Particularly, groups may want to establish a constant expansion factor and make that available to all users or they may want to make a certain subset of users that are key people in an organization and want to give them special services but only when their response time drops below a certain threshold. Given the prior art model, companies are unable to have the flexibility over their cluster resources.
To improve the management of compute resources, what is needed in the art is a method for a scheduler, such as a grid scheduler, a cluster scheduler or cluster workload management system to manage resources more efficiently. Furthermore, given the complexity of the cluster environment, what is needed is more power and flexibility in the reservations process.